“Trump will argue that the Paris pact is a bad deal for American workers and was poorly negotiated by the Obama administration,” according to the AP.

Here are nine things to know about the Paris climate agreement:

What is it?

The Paris climate agreement, also referred to as the Paris climate accord, the Paris climate deal or the Paris agreement, is a pact sponsored by the United Nations to bring the world’s countries together in the fight against climate change.

Countries that sign on to the pact agree to limit the century’s global average temperature increase to no more than 2 degrees Celsius (3.6 degrees Fahrenheit) above the levels from the years 1850-1900 (the pre-industrial era).

The agreement also imposes a more rigid goal of limiting temperature increases to only 1.5 degrees Celsius above pre-industrial era levels.

What is each country responsible for?

Under the agreement, every country has an individual plan (or “nationally determined contribution”) to tackle its greenhouse gas emissions.

For example, under the Obama administration, the U.S. vowed to cut its emissions by 26 to 28 percent below 2005 levels by the year 2025.

According to The New York Times, the Trump administration can either request a formal withdrawal, which takes four years, or it could withdraw from the United Nations Framework Convention on Climate Change altogether.

If the U.S. withdraws from the underlying convention, it would signal the country’s departure from any United Nations-sponsored climate discussions.

How would U.S. withdrawal affect national and global efforts against climate change?

According to The New York Times, a U.S. withdrawal could “seriously weaken global efforts to avoid drastic climate change.”

Instead of cutting emissions to 26 to 28 percent below 2005 levels by 2025 (the nation’s original pledge under the Obama administration), an analysis by Rhodium Group estimated that emissions would fall just 15 to 19 percent below 2005 levels.

“Pulling out of Paris is the biggest thing Trump could do to unravel Obama's climate legacy,” Axios' Jonathan Swan wrote early Wednesday. “It sends a combative signal to the rest of the world that America doesn't prioritize climate change and threatens to unravel the ambition of the entire deal.”

The effects of U.S. withdrawal on global efforts will depend heavily on how other countries react, but the nation could still face some diplomatic consequences for leaving, including possible carbon tariffs imposed on the U.S., The New York Times reported.

Would the U.S. be the only U.N. country not supporting the deal?

No, but the only other two U.N.-member countries that aren’t supportive of the Paris climate agreement are Nicaragua and Syria.